The amount of salary as fixed by any statute, heretofore or hereafter enacted, creating positions or fixing salaries for positions of any officer or employee of the State of Oklahoma, except as limited by Section 10 of Article XXIII of the Constitution of the State of Oklahoma, shall be and it is intended by the Legislature to be the maximum salary which each of the respective officers or employees shall receive or be entitled to receive; and none of such salaries, nor any part of any such salary shall constitute a valid claim against the State of Oklahoma in excess of the amount or amounts specifically appropriated therefor.